Electric spark-gap.



Patented Dec. 7, 1915;

mesma.

Wl /VE SSE S: www

BY C@ A fromm/Ey UllllTElDl STATES PATENT .@llelltli y FREDERICK G.SIMPSON, OF SEATTLE, WASHNGTON;

l ELECTRIC SPARK-GAP.

To (LU whom it may concern lle it known that I, lfnniniiiieii G.Surrsos', citizen of the United States, residing at Seattle, in thecounty of King and State of lllashingrtou. have invented a certain newand useful lniproveinent in Electric Spark- (laps` of which thefollowing isa specification.

Mv in ventioii relates to improvements in electric spai-lo-lcaps, andthe object ol" my improvement is to provide an electric sparklaap whoseoppositely disposed electrodes shall he iiiclosed in an air tight spaceWithin a structure wherein such electrodes shall be electricallyinsulated from eachother and be supported at a required distance apartbyilevices runde of materials having nearlyy like condiments of'expansion, due to heat, Where- .hv said electrodes mayv be maintainedsubtrated in tlu arconumnving drawings where-` iu-Fifrure l a plan viewof: a structure en'ibodying inlv invention, and Fig'. 2 is a view of thesaine in diauietriral section on broken liuc fr. ,fr of Fig'. l.

lie'lcrrinfr to the drawings, throughout which like reference nui'neralsindicate like parts, a disk fief inetal. is provided with an integraland concentricallv disposed annular' flange 4 which projects from the:upper side thereof, said flange 4 being provided with an externalscrew-thread and being of a si'naller external diameter-'than is thediameter of the periphery of the disk 3 whereby is provided an annular-shoulder or seat a lefainst which is disposed` the bottom surface of anannular and internally screw-threaded collar which is screwed on to theflange 4l.

The collar 5 is provided with a plurality of grooves G formed on 'itsperiphery Whereby there is a greater surface for the rac iation of'heatand it yis further provided with an inwardly projecting annular flangeabove the flange Llof the disk 3.

Specification of Letters Patent. Application filed March 20, 1915.Serial No. 15,864.

'disk 15 to the insulator 12.

'ikPatented Dec. "2', 1915.

The upper side surface 8 of the disk- 3 which is surrounded by 'theiange'if is preferably covered or `coated with silver, better to adaptit to serve as one of the electrodes of a spark-gap. i

T he bottom side of the disk 3 is provided with oppositely disposedcircular recesses 9,y

within which recessesl) may be inserted the studs of a Spanner wrench,andxthe upper,

side of the annular flange i' of `the collar 5 is provided with likerecesses y10 `within opposite ones of WlircliI may berinserted the studsof another Spanner wrench i'vhereby' such Spanner Wrenches may beoperated cciijointlj,T to screw the collar 5 on to and off from thefiaiig'eof the disk 3.

The bottom annular surface of 4the collar 5 and the adjacent annularsurface ofthe disk are accurately groundto engage eachother in thesai-ne plane whereby they may be ]oined to make an airtight engagementwith each other njhen the collar 5 is screwed to its fullest cxtenton tothe flange 4.

Secured by screws 11 to the underside o the flange 7 in a, positionconcentric with said flange T is an electric insulatory 12 o i I annularJforni ivliicli is provided on its upper side with an upvvardlj,Yprojecting' annular fl ange 13 and on its lower side with a downwardlyprojecting annularl flange 14, as shown in Fig. 2,

Secured to the underside of the annularly formed insulator 12 andconcentric .thereivith is a disk 15, of metal, which is provided vwith ahub portion 16 which projects upivardly into the opening through thecentral portion of the insulator 12, and such hub portion 16 is providedwith a coucentrically disposed screw-threaded recess into which isscrewed the screw-threaded boss 17 of a disk 'l8 of metal, .whose undersurface engages with the top surfacek of the insulator 12 whereby thedisk 15 is securely fixed to the underside of said insulator 12 whensaid disk 18 is turned to screw the boss 17 into the recess et the hubportion 16, there beine, provided dowel pins 19 iii the insulator 12 andthe disk-15, as shown in Fig. 2, to pre#vvrv vent the disk 15 fromturning when the disk 18 s turned in the operation of securingr theUppositely disposed recesses 2O are provided `in the upper side of thedisk 18 ivheref in may be inserted the studs of a spanner Wrench forturning' said disk 18.

Secured to the central portion et the top side of the disk 18 by meansof a screw 2l is an electrical contact 'spring 22, of sheet metal, whichextends radially to a point near the outer edge of the collar and whichis provided with an upwardly directed offset 23 to adapt the outer endportion of the spring 22 to assume a position parallel with the topsurface of the structure when it is pressed downwardly against aninsulating one on the top of the other to`form a series of spark-gaps,then the under surface of a disk, as the disk 3, of one structure, may

rest upon and make contact with the spring,

corresponding to the spring 22, of another structure pressing suchspring to rest against the insulating member corresponding to theinsulating member 24, thus disposin all the structures of the series inparalle planes with -each other and eleptrically connecting them inseries each with the others. To connect such a series in an electriccircuit one vterminal of such circuit may be provided with acontact plugwhich may beI disposed to fit within one of the recesses 9 of the .flowermost structure while the other terminal of such circuit may beconnected in any suitable manner to the disk corresponding 46 spondingto the screw 21.

. In assembling the parts of a structure, like the structure' of Figs. 1and 2, the annular surfaces of the lowerside of the4 collar 5' and `theupperside ofthe disk 3,-near its periphery, are accurately ground toremove enough metal to dispose the lower silver coated surface of vthedisk' 15 at a required4 short distance from theupper silver coatedsurface of the disk 3, thus when the, collar 5, with its associatedparts attached, is screwed to its full extent on to the annular flange 4then the space between said two silver coated surfaces of the adjacentelectrodes of .the spark-gap will be air tight.

In order that the required distance between said two silver coatedsurfaces may be maintained as nearly constant as possible irrespectiveof changes in the temperature of the different parts of the structure itis important that theI insulating member 12 shall be made of electricinsulating ,material having as nearly as possible thesame coefficient ofexpansion as is possessedY by the metal embodied in the disks 3 and 15and in the" vcollar 5 and by experiment I have found that a compositionknown by the trade name of f Lavite Ypossesses very nearly the same 7e Ywhich is molded by'molds into the form re- 75 quired, but I do notrestrict myself vto the use of any particular kind of metal or to theuse of f Lavite as an. insulating material in making the different partsof my invention.

The annular flanges 13 and 14 of the iii-@0 sulator 12 serve as shieldsagainst the transmission of sparks between the peripheries of the disks15 and 18 and Ythe adjacent surf faces of the flanges 7 and 4 thusconfining all sparking to the space between the silver coated surfacesof the disks 3 and 15.' W

In the structure thus described and illustrated it is mainfest that theairtight joints between the surfaces of the insulator 12 and thesurfaces of the disk 15 and Hangs 7 may 90 be permanent and undisturbedwhen the collar 5 is unscrewed from or screwed on to the flange 4 in theoperation of inspecting and cleaning the silver coated surfaces of theelectrodes, the ground metal joint be- Y tween the annular surfaces ofthe collar 5 -and the disk 3 being the only joint disturbed in suchoperation thus assuring that the distance Aacross the gap-space betweenthe electrodes shall always be the same when said collar is replaced inits normal position after such inspection, and, further, assuring thatsuch gap-space shall be airtight by reason of such ground metal joint.

Obviously changes may be made in the forms and dimensions of parts of myinvention without departing from the spirit thereof.

What I claim is:

l. In a structure of the class described, the

combination with a metal disk which is provided with an integral annularflange disposed to project from one side thereof, the surface of suchone side within' the circle of said annular flange being smoothv andfiat to adapt it to serve as one of the electrodes of a spark-gap, of aninwardly flanged collar removably disposed to surround said annularflange of said disk in engagement with said one side of said disk tomake an airtight joint therebetween, an insulator of electricity ofannular form secured in'a concentricV position to the inwardlyprojecting flanged portion of said collar, a second metal disk disposedwith one of its sides in airtight en- -gagement with the innerside'surface of said annulary insulator, while its other side prescntsits plane surface near t0 and parallel with said smooth flat surface ofsaid first named disk, thus to adapt it to serve as the 13| mames otherelectrode 4oI' such spark-gap, and separate means Yfor conneetingeach ofsaid disks with an electric circuit.

2. A structure of the class described, which embodies two electrodeseach having a flat surface and each being normally dis posed with suchflat surface adjacent to the like flat surface of the other, to form aspark-gap therebetween and means adapted both detaehably to suppert seidelectrodes in their normal relative positions and to inclose seidspark-gap to be air tight, said means comprising an insulator fastenedto one of said electrodes by e permanent airtight joint, and a meta-lsupporting mem ber permanently fastened to said insulator by anair-tight joint, saidv metal supporting member being detaehably fasteneddirectly to the other one of said electrodes to form a metallicair-tight joint therebetween.

In Witness whereof, I hereunto subscribe my naine this twelfth day ofMarch, A. D., 1915.

FREDERCK G. SIMPSGN.

Witnesses: l

FRANK VARREN, 0. JOHNSON.

